This invention relates to knitting.
1. Field of the Invention
It is known to use elastic threads such as those known by the names Lycra and Spandex (Registered Trade Marks) in various knitting techniques to produce stretch fabrics. Elasticised fabrics are made by laying in (power net) or knitting (stretch tricot) elastane or elastomeric yarns in warp knitting while in weft knitting elastic yarns are inlaid to produce elastically extensible fabrics.
2. Background Information
In U.S. Pat. No. 2,133,840 a dial and cylinder circular knitting machine produces two-way stretch fabrics for foundation garments in which an elastic body thread and an inelastic body thread are knitted to form connected but separate stitch loops and an auxiliary thread has ancillary loops knitted with certain of the body loops and long terry loops that project from one face of the fabric. The terry loops are deployed next to the wearer's skin for added comfort.
U.S. Pat. No. 2,720,097 discloses stretch heel and toe portions of tubular hosiery--so-called "surgical stockings"knitted from a wrapped elastic thread. At the heel and toe portions, a monofilament nylon year is introduced. With the elastic thread under a slight tension, the monofilament nylon thread plates to one face of the knitting which is then turned inside out so that the plated nylon thread is adjacent the heel or toe in use, for added comfort.
EP-0119 536-A1 discusses difficulties which arise when using a flat bed machine to knit an elastic yarn together with a ground yarn. In one arrangement, the ground yarn and elastic yarn are fed together to the yarn guide with the elastic yarn being taken through the ground yarn spool so that the ground yarn wraps around the elastic yarn. In another embodiment, the two yarns are fed separately using a plating thread guide so that the elastic yarn is plated by the ground yarn. In any event, it is necessary to give to the elastic yarn a definite pretension, which, seemingly, can only be done using a certain type of tensioner, namely a sintered ceramic thread tensioner. This is said to render tolerable the variations in tension in the elastic yarn which are due to the to-and-fro traverse motion of the yarn carrier.